IGFS AND NEUROBLASTOMA GROWTH

IGFS 和神经母细胞瘤生长

• 批准号: 2379698
• 负责人: Eva Lucille Feldman
• 金额: $ 11.47万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-04-01 至 1999-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2379698
• 关键词: antiantibody; athymic mouse; autocrine; carcinogenesis; cell growth regulation; cell transformation; growth factor receptors; insulinlike growth factor; laboratory mouse; nervous system; neuroblastoma; northern blottings; oncogenes; phenotype; polymerase chain reaction; recombinant proteins; transfection; tumor suppressor genes

Carcinogenesis is a multistep process (1). Cellular transformation can result from interactions between oncogenes, growth factors, growth factor receptors and growth suppressor genes (2). Autocrine production of growth factors, secondary to a loss of tumor growth suppressor gene activity, is one mechanism which allows malignant cells to maintain an unregulated proliferative state. One candidate growth factor, insulin-like growth factor II (IGF-II), can mediate autocrine growth of several malignancies (3,4), including Wilms tumor (5). Indeed, research on Wilms tumor has given insight to a potential mechanism underlying constitutive IGF-II production. The major fetal IGF-II promoter contains multiple binding domains for wt1, a zinc finger protein and member of the family of tumor growth suppressor genes (6). wt1, present in urogenital tissues (7), is a potent repressor of IGF-II transcription (8). Loss of IGF-II repression secondary to wt1 dysfunction is associated with the development of Wilms tumor (9,10). The objective of this proposal is to examine the role of IGF-II and potential IGF-II dysfunction in the growth regulation of a different cancer: human neuroblastoma (NBL). NBL is the second most common solid tumor in childhood (11) and accounts for 10% of all juvenile cancer (12). Histopathological examination of tumors reveals multiple neoplastic neural crest cell types, including neuroblasts, melanocytes, glial cells and chrondrocytes (13). Research on NBL has focused on the development of cell lines established from different NBL tumors (14). The SK-N-SH NBL cell line was derived from a 4 year old girl one month before her death (15). Analysis of clonal sublines of SK-N-SH reveal two distinct cell types: the SH-SY5Y clone consisting of N cells, or presumptive neuroblasts with small round cell bodies and neuritic processes (16) and the SHEP clone comprised of flattened substrate adherent cells with either glial, epithelial or melanocyte-like properties (16). SH-SY5Y cells exhibit serum independent growth, multiple in soft agar and form tumors in nude mice (16). In contrast cells, SHEP cells require serum and are unable to multiple in agar or form murine tumors(16). The current proposal focuses on the autocrine production of insulin-like growth factor-II (IGF-II) by NBL cells as one event in carcinogenesis . In this model, N cells (SH-SY5Y cells) produce IGF-II which acts as an autocrine N cell growth factor as well as a paracrine growth factor for S cells (SHEP cells), which do not produce IGF-II. These putative autocrine and paracrine loops are mediated via the type I IGF receptor and represent unregulated production of IGF-II secondary to loss of tumor growth suppressor gene activity. This proposal has three specific aims: 1. Determine if IGF-II, acting via the type I IGF receptor, can support the growth requirements of SHEP cells. 2. Determine whether deregulated expression of IGF-II alters the phenotype of SHEP cells. 3. Identify potential nervous system specific growth suppressor genes. Results gained from these studies are of definite clinical importance. Therapies aimed at interrupting the NBL IGF-II autocrine and paracrine loops may stop growth in all NBL cell types (17). Strategies include inhibiting both the ligand and receptor, using neutralizing antibodies, blocking antibodies, modified oligonucleotides or compounds which indirectly block IGF-II action, such as suramin (18). Clearly, anti-growth factor therapy, targeted at specific genes, has both theoretical and practical appeal in the treatment of NBL.

致癌过程是多步过程（1）。细胞转化可以 癌基因，生长因子，生长因子之间的相互作用产生 受体和生长抑制基因（2）。自分泌生产 因素是肿瘤生长抑制基因活性丧失的因素，是 一种允许恶性细胞保持不受管制的机制 增殖状态。一个候选生长因子，类似胰岛素样生长 因子II（IGF-II）可以介导几种恶性肿瘤的自分泌生长 （3,4），包括Wilms肿瘤（5）。确实，对威尔姆斯肿瘤的研究有 洞悉本构型IGF-II的潜在机制 生产。主要的胎儿IGF-II启动子包含多种结合 WT1的域，锌指蛋白和肿瘤家族的成员 生长抑制基因（6）。泌尿生殖组织中存在的WT1（7）是 IGF-II转录的有效阻遏物（8）。 IGF-II抑制的丧失 WT1功能障碍继发于Wilms的发展 肿瘤（9,10）。该提议的目的是检查 IGF-II和潜在的IGF-II功能障碍在A的生长调节中 不同的癌症：人类神经母细胞瘤（NBL）。 NBL是童年中第二大最常见的实体瘤（11）和帐户 在所有少年癌中的10％（12）。组织病理学检查 肿瘤揭示了多种肿瘤神经rest细胞类型，包括 神经细胞，黑色素细胞，神经胶质细胞和铬细胞（13）。研究 NBL专注于从 不同的NBL肿瘤（14）。 SK-N-SH NBL细胞系来自4 她去世前一个月（15）。克隆额定线的分析 SK-N-SH揭示了两种不同的细胞类型：SH-SY5Y克隆 N细胞，或具有​​小圆形细胞体的推定神经细胞和 神经过程（16）和由扁平的Shep克隆 具有神经胶质，上皮或黑色素细胞状的底物粘附细胞 属性（16）。 SH-SY5Y细胞表现出血清独立的生长，多个 在软琼脂中，在裸鼠中形成肿瘤（16）。在对比细胞中，Shep 细胞需要血清，并且无法在琼脂中多重或形成鼠 肿瘤（16）。 当前的提案重点是类似胰岛素的自分泌产生 NBL细胞作为癌变的一个事件，生长因子-II（IGF-II）。在 该模型N细胞（SH-SY5Y细胞）产生的IGF-II充当 自分泌N细胞生长因子以及S的旁分泌生长因子 细胞（SHEP细胞），不产生IGF-II。这些假定的自分泌 和旁分泌环通过I型IGF受体介导并表示 继发于肿瘤生长损失的IGF-II的不受管制的产生 抑制基因活性。 该提议具有三个具体目标：1。 确定通过I型IGF受体作用的IGF-II是否可以支持 Shep细胞的生长要求。 2。确定是否受管制 IGF-II的表达改变了Shep细胞的表型。 3。识别 潜在神经系统特异性生长抑制基因。 从这些研究中获得的结果具有明确的临床重要性。 旨在中断NBL IGF-II自分泌和旁分泌的疗法 循环可能会停止所有NBL细胞类型的生长（17）。策略包括 使用中和抗体抑制配体和受体， 阻断抗体，修饰的寡核苷酸或化合物 间接阻止IGF-II作用，例如苏拉明（18）。显然，反发展 针对特定基因的因子疗法具有理论和 在治疗NBL方面的实际吸引力。